System and method for guidance and implantation of implantable devices

Abstract

Systems and methods are provided for fixation of a fractured bone with an intramedullary bone fixation device. During an implantation procedure, the fixation device may be guided by a removable guidewire which is not coupled to the fixation device. The guidewire and device may be inserted into an intramedullary canal along a pathway which is not parallel to the intramedullary canal. The fixation device may be composite, formed of a support structure and a matrix material. The matrix material may be thermo-chemically activated, transformable from a deformable first thermo-chemical state to a hardened second thermo-chemical state. The fixation device may be radially expandable to deform to the shape of the intramedullary canal, to provide support to the fractured bone.

The invention claimed is: 
     
       1. A system for stabilizing a fractured bone, the system comprising:
 an implantable device comprising a polymer having a glass transition temperature greater than 37 degrees celsius, wherein the implantable device is deformable at a first thermo-chemical state in which the temperature of the polymer is greater than the glass transition temperature, and hard at a second thermo-chemical state in which the temperature of the polymer is lower than the glass transition temperature, the device, while the polymer is in the first thermo-chemical state, being responsive to a deforming force to deform from a first shape to a second shape, and the device, while the polymer is in the second thermo-chemical state, maintaining the second shape in a relatively rigid configuration to provide reinforcement to the fractured bone sufficient to promote healing of the fractured bone; and 
 a guidewire configured to be removably coupled to the implantable device, the guidewire configured to cooperate with the implantable device to guide placement of the implantable device during an implantation procedure. 
 
     
     
       2. The system of  claim 1 , wherein the implantable device comprises an intramedullary bone fixation device having an elongated shape, wherein the guidewire is configured to be removably insertable into the intramedullary canal of a bone along a pathway, at least a portion of which is not parallel to the intramedullary canal of the bone and the implantable device is deformable in the first thermo-chemical state to follow the path. 
     
     
       3. The system of  claim 1 , wherein the implantable device comprises a cannula, wherein the cannula is shaped to fit around the guidewire such that the guidewire can pass through the implantable device. 
     
     
       4. The system of  claim 1 , wherein the implantable device comprises an intramedullary bone fixation device configured to be deformable to the shape of an intramedullary canal of a bone. 
     
     
       5. A system for stabilizing fractured bone having an intramedullary canal, the system comprising:
 a composite intramedullary bone fixation device comprising a polymer having a glass transition temperature greater than 37 degrees Celsius and being deformable at a first thermo-chemical state in which the temperature of the polymer is greater than the glass transition temperature and hard at a second thermo-chemical state in which the temperature of the polymer is lower than the glass transition temperature, the device, while the polymer is in the first thermo-chemical state, being responsive to a deforming force to deform from a first shape to a second shape, and the device, while the polymer is in the second thermo-chemical state, maintaining the second shape in a relatively rigid configuration to provide reinforcement to the fractured bone sufficient to promote healing of the fractured bone; and 
 a guidewire configured to be removably coupled to the composite intramedullary bone fixation device, wherein the guidewire is configured to cooperate with the composite intramedullary bone fixation device to guide the composite intramedullary bone fixation device into the intramedullary canal of a bone. 
 
     
     
       6. The system of  claim 5 , wherein the composite intramedullary bone fixation device comprises:
 a matrix material including the polymer; and 
 a support structure. 
 
     
     
       7. The system of  claim 5 , wherein the guidewire is configured to be removably insertable into the intramedullary canal of a bone along a pathway, at least a portion of which is not parallel to the intramedullary canal of the bone. 
     
     
       8. The system of  claim 5 , wherein the composite intramedullary bone fixation device comprises a cannula, wherein the cannula is shaped to fit around the guidewire such that the guidewire can pass through the composite intramedullary bone fixation device. 
     
     
       9. The system of  claim 5 , wherein the composite intramedullary bone fixation device is configured to be deformable to the shape of an intramedullary canal of a bone. 
     
     
       10. A system for stabilizing fractured bone having an intramedullary canal, the system comprising:
 a deformable intramedullary bone fixation device having an elongated shape capable of being positioned within the intramedullary canal of a bone, the intramedullary bone fixation device comprising a polymer having a glass transition temperature greater than 37 degrees Celsius and being deformable at a first thermo-chemical state in which the temperature of the polymer is greater than the glass transition temperature and hard at a second thermo-chemical state in which the temperature of the polymer is lower than the glass transition temperature, the device, while the polymer is in the first thermo-chemical state, being responsive to a deforming force to deform from a first shape to a second shape which conforms to a surrounding portion of the bone, and the device, while the polymer is in the second thermo-chemical state, maintaining the second shape in a relatively rigid configuration to provide reinforcement to the fractured bone sufficient to promote healing of the fractured bone; and 
 a guidewire configured to be removably coupled to the deformable intramedullary bone fixation device, wherein the guidewire is configured to cooperate with the deformable intramedullary bone fixation device to guide the placement of the deformable intramedullary bone fixation device into the intramedullary canal of a bone. 
 
     
     
       11. The system of  claim 10 , wherein the deformable intramedullary bone fixation device is radially deformable along a length of the elongated shape to deform to the shape of the intramedullary canal of the bone. 
     
     
       12. The system of  claim 10 , wherein the deformable intramedullary bone fixation device is radially expandable along a length of the elongated shape to expand to conform to the shape of the intramedullary canal of the bone. 
     
     
       13. The system of  claim 10 , wherein the polymer has a glass transition temperature between about 50 degrees Celsius and 80 degrees Celsius. 
     
     
       14. A method for stabilizing a fractured bone having an intramedullary canal, the method comprising:
 inserting a guidewire into the intramedullary canal of a bone; 
 heating an elongated implant comprising a polymer above its glass transition temperature to transform it into a deformable state; 
 guiding the implant along the guidewire into the intramedullary canal of the bone while it is in the deformable state; and 
 removing the guidewire such that the implant remains in the intramedullary canal. 
 
     
     
       15. The method  claim 14 , wherein inserting the guidewire further comprises inserting the guidewire along a pathway, at least a portion of which is not parallel to the intramedullary canal of the bone. 
     
     
       16. The method of  claim 15 , wherein guiding the implant further comprises deforming the implant to follow the pathway. 
     
     
       17. The method  claim 14 , further comprising:
 deforming the implant to deform to the shape of the intramedullary canal of the bone to stabilize the bone. 
 
     
     
       18. The method of  claim 14 , further comprising:
 transforming the implant from a first thermo-chemical state to a second thermo-chemical state to harden the implant by cooling the polymer below its glass transition temperature, and the implant, while the polymer is in the second thermo-chemical state, maintaining the second shape in a relatively rigid configuration to provide reinforcement to the fractured bone sufficient to promote healing of the fractured bone. 
 
     
     
       19. A method for stabilizing a fractured bone having an intramedullary canal, the method comprising:
 inserting a guidewire into the intramedullary canal of a bone; 
 heating an elongated composite intramedullary bone fixation device comprising a polymer above its glass transition temperature to transform it into a first, deformable state; 
 guiding the composite intramedullary bone fixation device along the guidewire into the intramedullary canal of the bone while it is in the deformable state; and 
 allowing the composite intramedullary bone fixation device to cool below its glass transition temperature to transform it into a second state in which it provides reinforcement to the fractured bone sufficient to promote healing of the fractured bone. 
 
     
     
       20. The method of  claim 19 , wherein the composite intramedullary bone fixation device comprises a matrix material including the polymer and a support structure. 
     
     
       21. The method of  claim 20 , wherein inserting the guidewire further comprises inserting the guidewire along a pathway, at least a portion of which is not parallel to the intramedullary canal of the bone. 
     
     
       22. The method  claim 21 , wherein guiding the composite intramedullary bone fixation device further comprises deforming the composite intramedullary bone fixation device to follow the pathway. 
     
     
       23. The method of  claim 20 , further comprising:
 deforming the composite intramedullary bone fixation device to deform to the shape of the intramedullary canal of the bone to stabilize the bone. 
 
     
     
       24. The method of  claim 23 , wherein deforming the composite intramedullary bone fixation device further comprises radially expanding a length of the composite intramedullary bone fixation device. 
     
     
       25. A method for stabilizing a fractured bone having an intramedullary canal, the method comprising:
 inserting a guidewire into the intramedullary canal of the bone; 
 heating an elongated intramedullary bone fixation device comprising a polymer above its glass transition temperature to transform it into a first, deformable state, the intramedullary bone fixation device having a lengthwise passage; 
 guiding the intramedullary bone fixation device along the guidewire into the intramedullary canal of the bone by engaging the guidewire with the lengthwise passage; 
 removing the guidewire such that the intramedullary bone fixation device remains in the intramedullary canal of the bone. 
 
     
     
       26. The method of  claim 25 , further comprising deforming the intramedullary bone fixation device by radially deforming the intramedullary bone fixation device along a length of the intramedullary bone fixation device. 
     
     
       27. The method of  claim 25 , further comprising deforming the intramedullary bone fixation device by radially expanding the intramedullary bone fixation device along a length of the intramedullary bone fixation device. 
     
     
       28. The method of  claim 25  wherein the polymer has a glass transition temperature between about 50 degrees Celsius and 80 degrees Celsius. 
     
     
       29. The method of  claim 25  further comprising cooling the polymer below its glass transition temperature.